In iOS 7, Apple introduced the possibility to [execute JavaScript via the JavaScriptCore JavaScript engine] (http://nshipster.com/javascriptcore/). Unfortunately, JavaScriptCore is missing some objects and functions a JavaScript environment of a browser would have. Especially the XMLHttpRequest (see the [Mozilla documentation] (https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest) object needed for AJAX requests is not provided by JavaScriptCore. This library implements this missing object, so it is possible to use JavaScript libraries which were originally developed for in-browser use in your Objective-C (or Swift) application without the need to use a hidden WebView.

This library tries to implement the full XMLHttpRequest specification. Currently not all functionality is implemented yet. The current limitations are:

• Synchronous calls are not supported.
• The onload and onerror callbacks are currently not supported.
• The upload callback is currently not supported.
• The timeout property is currently not supported.

It is planned to support all functionality of the HTML5 specification at some point.

Create a new instance of the XMLHTTPRequest class. Then call the extend: method and pass either a JSContext instance or a JSValue instance. The given object will be extend with the XMLHTTPRequest object.

#import <XMLHTTPRequest/XMLHTTPRequest.h>

...

JSContext *jsContext = [JSContext new];
XMLHttpRequest *xmlHttpRequest = [XMLHttpRequest new];
[xmlHttpRequest extend:jsContext];

The JavaScript context now has a XMLHTTPRequest object you can use like the object found in browsers. Example (JavaScript):

request.open('GET', 'http://example.com');
request.setRequestHeader('Accept', 'text/html');
request.setRequestHeader('X-Foo', 'bar');
request.send();

If you are interested in more polyfills for missing browser functionality in JavaScriptCore, there is a window timers implementation (setTimeout, setInterval, ...) called [WindowTimers] (https://github.com/Lukas-Stuehrk/WindowTimers).